Computer users today frequently use their computers and computerized devices, such as handheld computers and cell phones, in a mobile manner. For example, in the past a computer user may have expected only to read his or her e-mail while at a main desktop computer at the office, where this main computer was constantly connected to the company network, and the Internet. However, users are now frequently connecting to network or communication facilities intermittently, from a variety of different locations and using a variety of different devices. For example, a user who travels frequently may connect his or her laptop to the office network while at the airport over a dial-up phone connection just before boarding the plane, or call the up the office network after checking into a hotel. A user may also have his or her e-mail forwarded to a pager, or a cellular phone, or to other forms of wireless network technology. These sorts of connections may be brief, to download some e-mail or other information, before disconnecting. Intermittency may also result even with optimally permanent connections. For example, more sophisticated mobile communications systems may allow for “always-on” wireless services, but in reality signal strength may not be sufficient in all the places users travel, such that the resulting connection is intermittent. Additionally, a system may be designed to limit its usage of bandwidth by only establishing connections and/or transmitting information intermittently.
Intermittent connections and even some permanent connections present difficulties in receiving important e-mail messages and other information, because of the constrained resources that frequently are inherent with such connections. For example, a cellular phone or a pager to which e-mail is being forwarded may only be able to receive a certain number of messages, such that each is of a certain length. As another example, a user in an airport who wishes to connect to his or her desktop or e-mail system over a public phone generally is limited to a relatively slow modem connection, and may not have much time to receive e-mail messages if the user is awaiting a connecting flight. For both of these cases, the user is likely to want to receive only or at least first the most important messages, and perhaps not receive attachments to the e-mail messages, junk mail messages, etc. However, this is not provided for by the prior art. For these and other reasons, there is a need for the present invention.